// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/mac/launchd.h"

#include "base/logging.h"
#include "base/mac/scoped_launch_data.h"

namespace base {
namespace mac {

    // MessageForJob sends a single message to launchd with a simple dictionary
    // mapping |operation| to |job_label|, and returns the result of calling
    // launch_msg to send that message. On failure, returns NULL. The caller
    // assumes ownership of the returned launch_data_t object.
    launch_data_t MessageForJob(const std::string& job_label,
        const char* operation)
    {
        // launch_data_alloc returns something that needs to be freed.
        ScopedLaunchData message(launch_data_alloc(LAUNCH_DATA_DICTIONARY));
        if (!message.is_valid()) {
            LOG(ERROR) << "launch_data_alloc";
            return NULL;
        }

        // launch_data_new_string returns something that needs to be freed, but
        // the dictionary will assume ownership when launch_data_dict_insert is
        // called, so put it in a scoper and .release() it when given to the
        // dictionary.
        ScopedLaunchData job_label_launchd(launch_data_new_string(job_label.c_str()));
        if (!job_label_launchd.is_valid()) {
            LOG(ERROR) << "launch_data_new_string";
            return NULL;
        }

        if (!launch_data_dict_insert(message.get(), job_label_launchd.release(),
                operation)) {
            return NULL;
        }

        return launch_msg(message.get());
    }

    pid_t PIDForJob(const std::string& job_label)
    {
        ScopedLaunchData response(MessageForJob(job_label, LAUNCH_KEY_GETJOB));
        if (!response.is_valid()) {
            return -1;
        }

        launch_data_type_t response_type = launch_data_get_type(response.get());
        if (response_type != LAUNCH_DATA_DICTIONARY) {
            if (response_type == LAUNCH_DATA_ERRNO) {
                LOG(ERROR) << "PIDForJob: error "
                           << launch_data_get_errno(response.get());
            } else {
                LOG(ERROR) << "PIDForJob: expected dictionary, got " << response_type;
            }
            return -1;
        }

        launch_data_t pid_data = launch_data_dict_lookup(response.get(), LAUNCH_JOBKEY_PID);
        if (!pid_data)
            return 0;

        if (launch_data_get_type(pid_data) != LAUNCH_DATA_INTEGER) {
            LOG(ERROR) << "PIDForJob: expected integer";
            return -1;
        }

        return launch_data_get_integer(pid_data);
    }

} // namespace mac
} // namespace base
